/*
 * #!
 * Ontopia Engine
 * #-
 * Copyright (C) 2001 - 2013 The Ontopia Project
 * #-
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 * 
 *      http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 * !#
 */

package net.ontopia.persistence.query.jdo;

/**
 * INTERNAL: Represents an aggregate function in a JDO query. An
 * aggregate function can be used as part of the select and ordering
 * components of a JDO query.
 */

public interface JDOAggregateIF {

  /**
   * INTERNAL: Constant referring to the COUNT aggregate function.
   */
  int COUNT = 1;

  /**
   * INTERNAL: Returns the aggregate function type indicated by one of
   * the constants in the {@link JDOAggregateIF} interface.
   */
  int getType();

  /**
   * INTERNAL: Returns the JDOValueIF that the aggregate function is
   * to be evaluated against.
   */
  JDOValueIF getValue();
  
}





